Charge transport and injection to phenylamine-based hole transporters for OLEDs applications

We studied the hole injection and transporting properties of four phenylamine-based hole-transporters useful for organic light-emitting diodes. The hole-transporting properties were examined in details by time-of-flight technique whereas their hole-injecting properties by current-voltage measurements and dark-current space-charge-limited-current technique (DI-SCLC). All materials were found to exhibit essentially trap-free hole transports. We discovered that a conducting polymeric anode, PEDOT:PSS, can act effectively as an Ohmic contact for hole injection into the PA compounds for DI-SCLC experiments.